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-   -   Memory usage of pimpleFoam in parallel (https://www.cfd-online.com/Forums/openfoam-solving/235061-memory-usage-pimplefoam-parallel.html)

hconel March 30, 2021 12:11

Memory usage of pimpleFoam in parallel
 
Hi,
I am running LES using pimpleFoam on 20 physical cores. Mesh size is around 7 millions. In the Task Manager window, I see 20 "pimpleFoam -parallel" processes, each using 2.4GiB of memory. Does that mean the total memory usage is 2.4 * 20 = 48GB? This looked too much for such a run, but also 2.4GiB total memory usage sounds too small.

https://i.ibb.co/DRK3xsW/Screenshot-...0-19-05-04.png
65 png

So which one should I consider?
Best regards,
Huseyin

Specs:
24-core AMD Threadripper 3960x CPU
64GiB of memory
OS: Xubuntu 20.04

Tobermory March 31, 2021 16:18

The task manager is reporting all the processes. When you decompose to run on 20 processors, you spawn 20 processes ... so each line you see in the task manager is a separate process, each of 2.4GB ... so yes, it is using 48GB in total.

The other way to check total memory usage is to open a terminal and type
Code:

free -h
That will report back the memory usage.


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